Then, in [1]} it is shown that under
the expected average power constraint \(P\)  on each of transmitters as,
\(\sum \limits _{i = 1}^n {{\gamma _i\mathop {\rm E}\nolimits } \left\lbrace  {X_{\left( k \right)i}^2 } \right\rbrace } \le nP;\;\;k = 1,2\) 
